The invention provides a reactor body and a multifunctional 
airlift tube 
photobioreactor. The reactor body, namely a reaction device, comprises two or more transparent perpendicular pipelines arranged side by side, and connecting tubes or connecting grooves communicated with the tops and the bottoms of the perpendicular pipelines respectively. The 
photobioreactor comprises the reactor body, a ventilation 
system and an optional parameter detection and 
control system. The invention further provides a microalgae culture method which comprises the step that the reactor body or the 
photobioreactor is used for carrying out photoautotrophic culture, photoinduction culture and mixotrophic 
nutrition culture of the microalgae. The multifunctional 
airlift tube photobioreactor has the advantages of being large in illumination specific surface area, high in gas-liquid 
mass transfer coefficient, small in 
fluid shear force and the like; 
engineering enlargement, cleaning and maintenance are easy, operation is convenient, high-density, high-efficiency and large-scale photoautotrophic culture, photoinduction culture and mixotrophic 
nutrition culture of the microalgae can be achieved, high-efficiency culture of 
photosynthetic bacteria can also be achieved, and meanwhile the multifunctional 
airlift tube photobioreactor can be used for microalgae 
carbon sequestration and 
wastewater treatment.